Improvement in machines for mining coal



H. SPEAR.

Machine for Mining Coal.

No. 133,900. I Pat ented De 16,1872.

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UNrrEnSTATEs PATENT QFFICE. w.

HATHERLY SPEAR, or PORTLAND, MAINE, 'ASSIGNOR or ONE-THIRD Hrs RIGHT TOJOHN 0. ROBINSON, or BLACK ROCK, connncrrcur.

IM'PRQVEMENQT IN MACHINES'FOR MINING COAL.

Specification forming part of Letters Patent No. 133,900, dated December10, 1872.

and exact description ofthe same, reference being had to theaccompanying drawing forming part of this specification, in which Figurel is a top-plan view of myimproved machine; Fig. 2 is a perspective viewof the same; and Fig. 3, an end elevation.

Similar letters of reference in the accompaing drawing indicate-the sameparts.

My invention has for its object to provide for general use a coal-miningmachine operated by compressed air; and to this end it consists incombining a sliding'drill with a compressed-a1r cylinder, and inmounting both drill and cylinder upon an adjustable frame, so that theformer can be adjusted horlzontally and vertically to operate at anynecessary angle, as I will now proceed code-- scribe.

ln theaccompanying drawing, A represents 1 a suitable platform-car, uponwhich is pivoted an upright or center post, B, in such a manner as toturn freely. .I prefer to construct the upright in the form of a cone,provided at its base with a segmental rack, O, to en gage with a pinionor lantern wheel, D,

mounted in a suitable frame beside the upright, and operated by ahand-wheel, E, as shown. The upright is further provided with two sidepieces, I, extending above its apex or top, to receive the trunnions gof the drillframe or sides H H, which carry the drill and compressed-aircylinder P. The latter is firmly secured midway between the sides H, andthe drill I passes longitudinally through ltscenter, being guided by theends of the sides H, which are bent so as to form short tubes orguide-rings, as shown. If desired, hoWe ver,-the sides may be omitted,the drill being guided whollyby the cylinder, and the latter providedwith the trunnions g. J are springs coiled spirally around the drill ateach end of the cylinder, one end of each being secured to the cylinderand the opposite end to the drill.- The compressed air is conducted intothe top of the cylinder, at about the center thereof, by means of apipe, K, connected to a suitable compressor.

When the drill is to be operated, the compressed air is let into thecylinder against the front end thereof, and a suitable piston mountedupon the drill a little in rear of the air-induction port. Thepressurevof the air moves the piston and drill backward against thetension of the spring J until the piston reaches the rear end of thecylinder, when the air is exhausted from the latter, or its pressurerelieved in any suitable manner, and the springs J drive the drillforward with great force against the coal.

The pressure of the air upon the piston may be relieved in anyconvenient manner, either in the cylinder or supply-pipe. Instead ofdriving the drill by the springs, and moving it back by the compressedair, this arrangement may be reversed, so that the compressed air shalldrive the drill forward and the springs retract it.

L is a segmental rack secured to one of the sides, H, at or near itslower edge, in such a position as to engage with a lantern-wheel orpinion, M, the shaft of which has its bearings in the side pieces I.

By operating the hand-wheel 0 upon the shaft, the drill is swungvertically upon its trunnions to adjust the angle at which it shalloperate against the coal.

The operation of the hand-wheel E adjusts the angle of thedrillhorizontally withrespect to the car or truck upon which it ismounted, as will be readidy understood.

Having thus described my invention, what vI claim is- 1. A coal-miningmachine in which the drill is operated by springs and compressed air,and adapted for horizontal and vertical adjustment, substantially asdescribed, for the purpose specified.

2. A coal-mining machine in which an ad.-

jnstable spring-drill is adapted to operate di- 4. In combination withthe pivoted ups rectly through at compressed-air cylinder, subright B,the spring-drill, and the compressedstantially as herein described, forthe purpose air cylinder P, the drill-frame H H, substanspecifivd.tially as described, for the purpose specified.

3. The combination of the springs J and HATHERLY SPEAR. drill l with thecompressed-air cylinder, sub- 7 Witnesses: stmitia-lly as described, forthe purpose'specii JOHN E. Dow,

tied. f

NATHAN CLEAVES.

